The invention relates to a stator-rotor arrangement for vacuum pumps, in particular for turbomolecular pumps.
Vacuum pumps, such as turbomolecular pumps, comprise a rotor element surrounded by stator disks. In this arrangement, the stator disks extend between the individual rotor disks of the rotor element, with the stator disks being usually formed as half rings. In the longitudinal direction of the rotor, which normally corresponds to the pumping direction, the stator disks are arranged in series in alternate arrangement with rotor disks. For fixation of the stator disks, stator rings are provided. A stator disk is held in a form-closed manner by respectively two adjacent stator rings. Thus, the stator rings are stacked onto each other. For assembly, two half disks forming a stator disk will have to be arranged alternately with annular stator rings surrounding the stator element, whereupon the stator-rotor arrangement will be inserted into a housing comprising a cylindrical recess. Consequently, the assembly process is extremely bothersome.
From U.S. Pat. No. 6,457,954, it is known to arrange the rotor element together with the stator disks and the stator rings in a cylindrical cartridge. This cartridge will then be arranged in the housing. In this manner, the stator-rotor arrangement can be pre-assembled within said cartridge. In order to realize such a pre-assembly, however, an additional component in the form of said cartridge is required.
It is an object of the invention to provide a stator-rotor arrangement which can be pre-assembled in a simple manner.